Radius truing attachment



Sept. 30, 1941. A. J. GRAF RADIUS TRUING ATTACHMENT Filed Jan. 25, 1940 2 Sheets-Sheet l .F R OW M v N I w \N N T .Q MN m R A ATTORNEY.

Sept. 30, 1941. A. J. GRAF RADIUS TRUING ATTACHMENT 2 Sheets-Sheet 2 Filed Jan. 25, 1940 IN VENT OR. v Mafia J62;

cum i ATTORNEY.

- Patented Sept. 30, 1941 UNITED STATES" PATENT OFFICE;

RADIUS TBUlNQ ATTACHMENT Andrew J. Graf, Norwood, Ohio, minor to Cincinnati Grinders Incorporated, 7 Cincinnati, Ohio, a corporation of Ohio Application January 25, 1940, Serial No. 315,475

. 11 Claim.

This invention relates to the grinding art and more particularly to truing mechanism for grinding wheels.

One of the objects of this invention is to provide improved means for truing a formed surface on the periphery of a grinding wheel;

Another object of this invention is to provide an improved radius truing attachment for grinding machines.

Other objects and advantages of the present, invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Referring to the drawings in which like refm ure 1.

Figure 3 is a section on line 3-3 of Figure 1.

Figure 4 is a section on the line 4-4 of Figure 1.

Figure 5 is a detailed view' as viewed on the 80 line 5-5 of Figure l. c

Figure 6 is a section on the line 8-6 of Figure 5.

Figure '7 is a detail view on the line 1-1 of Figure 2.

This invention deals with a truing mechanism which isso designed that it is adaptable to be mounted on the guard which surrounds the grinding wheel in such a manner as to protect the operator in case of. wheel breakage and incidentally to confine the coolant spray which is usually applied to the wheel during a. grinding operation. Thus, the mechanism is always in position for utilization at any time without interference in any way with the work or ilxbe supported in any conventional manner on a 0 fixed part of the machine, but since this forms y no part of the present invention such; support is not shown. The truing mechanism constituting this invention is adapted to true the periphery of the grinding wheel to a semi-circle imparted to the truing tool in a direction toward in cross section andis adjustable for variations in wheel width, as well as for wheel wear.

The-truing mechanism comprises a tubular housing 12 which is attached to the guard in such manner as to provide for lateral adjustment with respect to the plane of rotation of the grinding'wheel. The housing has a bore l3 whose axis lies in a radial plane of the wheel for slidingly'receiving a stud H attached to and supporting a yoke l5. In order to prevent any rotary movement of the yoke about its axis, a key I8 is provided between the stud and the housing. The yoke supports a diamond carrier I! which is supported for rotation on the yoke about axis l8, and the carrier supports a diamondor truing tool l9 whichhas a truing point 20 that lies on the axis 2| which constitutes the axis of movement of the stud.

The intersection 22 of axes l8 and 2| represents the center of rotation of the truing point.

It will now be evident that when the stud is moved axially that it will cause the truing point to move along the axis 2| and since this axis is a prolongation of the radius 23 of the grinding wheel, the truing point when rotated about the center 22 will move in a radial plane of the grinding wheel and thus provide a true arcuate or convex surface on the periphery of the wheel.

The stud I4 is shifted by a feed screw 24 which is anchored against axial movement at 25 in the housing and is threaded through a nut 26 mounted in the end of a bore 21 formed in the end of the stud. The bore 21 is elongated beyond the inner end of the nut to provide clearance for the screw. An operating gear 28 is keyed to the end of the screw and intermeshes with a second gear 29 fixed to the end of an operating shaft 30. A manually rotatable hand wheel 3| is secured to the end of the shaft 30 and is provided with graduations 32 .which register with a fixed reference mark 33 scribed on the end of an arm 34 attached to the end of a housing 35. The arm is clamped against rotation to the housing by a clamping screw 35, but

by loosening the clamping screw, the arm 33 may be adjusted about the axis of the shaft 30 to position the zero reference mark 33 relative to any graduation mark on the hand wheel to suit the convenience of the operator and to assist in determining the lengths of movement of the truing tool.

Thus rotation of the hand wheel 3| determines the amount of feeding movement to be One end of the yoke carries a housing 31 for enclosing the operating mechanism for effecting rotation of the carrier H about the axis IS. The carrier i! is integral with the lower end of a shaft 38 which has a tapered bearing 39 by which it is held against axial movement by anti-friction thrust bearings 40. A worm wheel 46 is fixed to the upper end of the shaft and intermeshes with a worm 42 which is adapted to be rotated by a hand wheel 43. It will be noted that the worm and worm wheel form a reduction unit between the hand wheel and the carrier whereby a slow accurate rotation may be imparted to the truing tool, and in addition, since the worm and worm wheel are self-locking, the carrier II will be held against rotation in any position that it happens to stop. The end of the yoke I5 which supports housing 31 has a reduced portion 44 which passes through an aperture 45 formed in the guard l and it will be noted that since the yoke l is movable with the stud I4 in one plane and also laterally movable with the housing I2 in a second plane at right angles to the first, the'aperture 45 must be made of sufficient dimensions to take care of both of these movements. Therefore, it is necessary to provide a large cover plate 46. Means are provided for clampingthe cover plate to the guard in spite of the two directions of movement of the plate and this means comprises a clamping bolt 41 which, as shown in Figure 6, passes through a hole 48 in the guard ID, the hole being elongated as shown in Figure 5 to takecare of one direction of movement while the bolt passes through a second hole'49 in the plate 46, which is elongated l as shown in Figure 5 in a direction perpendicular to the long axis of the hole 48, to take care of the second direction of movement.

The square head 50 on one end of the bolt is guided by a strip 5! attached to the underside of the guard and this holds the bolt against rotation when the clamping nut 52 threaded on the other end of the bolt is rotated.

The amount of rotation of the carrier H is limited to 180 degrees and this limiting means is shown in Figure 3 of the drawings. The shaft 38 is provided with a radial pin 53 which engages the end of a set crew 5% for limiting the rotation in one direction, while the end of a set screw 55 limits the rotation in the other direction. These set screws are threaded in the yoke i5 and are clamped in adjusted position by clamping screws 56.

Various widths of grinding wheels may be applied to the end of the grinding wheel spindle 51 shown in Figure 2 and such spindles usually have a fixed flange 58 against which one face of the grinding wheel is placed and then a second flange is mounted on the end of the spindle and clamped against the opposite face of the grinding wheel.

Thus, the position of the center of the face of the grinding wheel will vary in accordance with the width of the wheel. It is necessary, of course, that the center of rotation of the truing tool lie in the plane which passes through the center of the 'face of the grinding wheel. It is, therefore, necessary to provide for lateral adjustment of the housing l2 relative to the guard ID in order that the plane of movement of the'feed screw and the center of rotation of the carrier all lie in the central plane of the grinding wheel.

This is accomplished by providing six clampingscrews 59 which, as shown in Figure 1, are

threaded into the guard and as shown in Figure 2 pass through elongated holes iii formed in the flange SI of the housing l2. when the screws 59 are loosened, a pair of adjusting screws 62 are rotated in one direction to efiect adjustment of the housing to the right as viewed in Figure 2, while a second pair of set screws 63 are rotated to effect adjustments to the left. To assist in locating the housing in accordance with the width of the wheel, suitable graduations G4 are applied tothe flange ,6! for cooperation with a fixed reference mark 85 carried by the guard It to indicate the position of the housing for each wheel width. When a change in wheel width is truing point is supported in a bore 66 in the carrier l1 and held against rotation .by a pin 61 which rides in a groove 68 formed longitudinally of the holder. The holder I8 is shown in Figure 4 in its maximum outward position as respects the axis'of rotation 22 and inward movement is efiected by rotating a nut 69 which is threaded on the reduced threaded end 10 of the holder IS.

The nut 69 has an annular flange H and by means of this flange the nut 69 is clamped against axial movement between a shoulder 12 on the carrier H and a plate 13 which is fastened to the carrier by screws I4. An operating collar I5 is secured to the end of the nut by a set screw 16 and this collar carries graduations 11 which 00- operate with a zero mark I8 on the fixed member 13 toshow the efiective radius of the truing point. To increase the range of adjustment a second holder may be substituted for the holder l9 which is of greater length so that the efiective radius may be graduated down to zero.

Since the radius adjusting mechanism for the truing tool is supported between the guard and the grinding wheel and therefore inaccessible, a removable cover plate 19, Figure 7, is slidably mounted between guides 80 on the guard, and when the cover plate is removed by knobs 8|, an

opening 82 in the guard is uncovered providing the combination with a guard for said wheel, of

a housing mounted on said guard, a support member slidably mounted in said housing and guided for movement toward and from the axis of said wheel, a truing element pivotally supported bysaid member, means for adjusting the housing parallel to the. axis of said wheel to position the pivotal axis of said truing element in the central plane of said wheel, and cooperating graduation marks carried by the housing and the guard for indicating this position in accordance with the width of the grinding wheel.

2. In a truing mechanism fora grinding wheel, the combination with a guard for said wheel, of a tubular housing mounted on said guard with its axis lying in a radial plane of said wheel, a yoke mounted within said guard having a .stud protersecting th mung through the guard and guided in said tubular housing for movement parallel to the axis thereof, a carrier pivotally mounted in the ends of said yoke, a truing point mounted on the carrier, .the pivotal axis or the carrier intersecting the axis of the tubular housing, an extension on said yoke projecting through-the guard at a point remote from said housing, and meansmounted on-said extension exterior oi the guard for rotating said carrier to cause the truing point to produce an arcuate suriace on the periphery of the wheel.

3. In a truing mechanism for a grinding wheel,

graduations on the hand wheel cooperating with said reference mark to :indicate the amount of the combination with a guard for said wheel, of

a tubular housing mounted on said guard with its axis lying in a radial plane of said wheel, a yoke mounted within said guard having a stud projecting through the guard and guided in said tubular housing for movement parallel to the axis thereof, a carrier pivotally mounted in the ends or said yoke, a truing point mounted on the carrier, the pivotal axis of the carrier intersecting the axis of the tubular housing, an extension movement imparted to the truing point, and means to adjust said arm relative to said support to position the reference mark adjacent any graduation on said hand wheel. v

7. In a truing mechanism for a grinding wheel, the combination with a guard for said wheel having a pair of apertures formed therein, a yoke on said yoke projecting through the guard at a point remote from said housing, means mounted on the guard and engaging said extension exterior of the guard for rotating said carrier to cause the truing point to producean arcuate surface on the periphery of the wheel, and mechanism mounted on the housing ior adjusting said yoke to move the truing point toward the wheel.

4. In a truing mechanism for a grinding wheel, the combination with a guard for said wheel, of a tubular housing mounted on said guard'with its axis lying in a radial plane of said wheel, a yoke mounted within said guard having means projecting through the guard and guided in said tubular housing, a carrier pivotally mounted in theends of said yoke, a truing point mounted on the carrier, the pivotal axis of the carrier inaxis of the tubular housing at a point within he grinding wheel, an extension-on said yoke projecting through the guard at a point remote from said housing, actuating means mounted on said extension exterior of the guard mounted within the guard having portions projecting' through the respective apertures, a housing member adjustably mounted on the guard in circumscribing relation to one of the apertures and receiving one of the projections on the yoke,

means carried by said housing for effecting axial adjustment of the projection and thus of the yoke, an auxiliary housing carried by the other projection oi. theyoke and disposed in overlying relation to the guard adjacent the other aperture therein, a truing tool carrier oscillatably mounted on the yoke within the guard, and means carried by the auxiliary housing exteriorly of the guard for electing swinging movement of the yoke mounted within the guard having portions projecting through the respective apertures, a

and connections between said means and the carrier for oscillating the latter to produce an arcuate surface on the periphery of the grinding wheel. l

5. In a truing mechanism for a grinding wheel, the combination with a guard for said wheel, of a tubular housing mounted on said guard with its axis lying ina radial plane oi. said wheel, a yoke mounted within said guard and guided in said housing for movement in said radial plane, a carrier pivotallyv mounted in the ends'of said yoke, a truing point mounted on the carrier, the pivotal axis of the carrier intersecting the axis of the tubular housing within the grinding wheel, an extension on said yoke projecting through the guard at a point remote from said housing, a hand wheel mounted on said extension exterior or the guard and operatively connected for rotaing point toward the grinding wheel, a hand 6. In a truing mechanism for a grinding wheel,

the combination with a guard for said wheel, of a housing for supporting said mechanism, means toattach said housing to housing member adjustably mounted on the guard in circumscribing relation to one or the apertures and receiving one of the projections on the yoke, means carried by said housing for eiIecting axial adjustment of the projection and thus of the yoke, an auxiliary housing carried by the'other projection of the yoke and disposed in overlying relation to the guard adjacent the other aperture therein, a truing toolcarrier osciliatably mounted on the yoke within the guard, means carried by the auxiliary housing exteriorly of the guard for effecting swinging movement of the carrier, and means for securing the auxiliary housing to the guard to prevent oscillation of the yoke.-

9. In a mechanism of the character described, the combination with a grinding wheel and a guard surrounding the wheel, 01' means foreffecting a truing of the wheel within the guard including an oscillatable truing tool carrier, a

yoke pivotally supporting the carrier having a pair ofprojections, a support mounted on one of said projections exteriorly oi the guard, means for eflecting relative adjustment of the support and projection to vary the position oi the yoke within the guard in a direction toward and from the-wheel, means adjustably securing the support to the guard whereby unitary lateral adjustment of the yoke and support may be effected with respect to the guard, the guard having the guard, truing tool the combination with a grinding wheel and a guard surrounding the wheel, of means ior effecting a truing oi the wheel within. the guard including an oscillatable truing tool carrier, a yoke pivotally supporting the carrier having a pair of projections, a support mounted on one oi said projections exteriorlyof the guard, means for effecting relative adjustment of the support and projection to vary the position oi the yoke within the guard in a direction toward and from the wheel, means adjustably seeming the support to the guard whereby unitary lateral adjustment of the yoke and support may be eflected with respect to the guard, the guard having an aperture formed therein toreceive the other projection on the yoke, and means tor securing said projection in adjusted position with respect to the guard to prevent tilting of the device,

vfecting a truing of the wheel within the guard including an oscillatable truing'tool carrier, at

yoke pivotally supporting the carrier having a pair of projections, a support mounted on one of said projections exteriorly oi the guard, means foreflecting relative adjustmentoi' the support and projection to vary the position of the yoke withinthe guard in a direction toward and from the wheel, means adjustably securing the support to the guard whereby unitary lateral adjustment of the yoke and support may be eflected with respect to the guard. the guard having an aperture formed therein to receive the other projection on the yoke, means tor-securing said projection in adjusted position with respect to the guard to prevent tilting of the device, said securing means including an auxiliary housing disposed exteriorly oi the guard and actuating means for the truing tool carried. by the housing whereby the same may be rigidly supported on the guard, an actuating portion on the carrier extending exteriorly oi the guard by way of the projection on the yoke, and driving connections between the actuating means on the auntiliary support and said projection for eflecting truing oscillation of the carrier.

. ANDREW J. GRAF. 

